Defining bioactivities of peptides released from human milk proteins in the preterm infant intestine

项目总结 母乳，无论是母乳还是经巴氏杀菌的捐献者母乳，都被认为是 早产儿。除了作为支持婴儿生长的氨基酸来源外，人类乳汁蛋白质 编码婴儿消化过程中释放的隐秘生物活性多肽。这些多肽可以在婴儿体内找到 肠腔液和具有一系列生物活性，包括抗菌、致双歧、 免疫调节，以及对肠道生理的影响。虽然 多肽 负责任的 多肽 我们的初步研究表明，牛奶 在婴儿肠道中的释放和存在具有有益的活性，识别特定的多肽 对于这些与直觉相关的行动来说，一直是有限的。因此，迫切需要确定具体的 在婴儿的胃肠道中释放，调节这些生物活性。 我们的长期目标是利用母乳的生物学来促进最佳的发展和增长。 早产儿的子宫外。这项提议的总体目标是证明存在和身份 促进肠道健康的人类乳蛋白衍生多肽在早产儿肠道中的含量。我们的中央 假说认为，生物活性多肽在婴儿的肠道中释放，通过 微生物组、肠道上皮和免疫系统。我们的具体目标是确定抗菌剂 和双裂活性，2)肠上皮细胞(IEC)特异性效应(屏障功能，增殖， 分化)和3)早产儿肠道内容物中多肽的巨噬细胞免疫调节活性 喂食母乳的婴儿。对于这些活动中的每一个，我们都将识别和验证特定的多肽。我们的方法 将在新生儿重症监护病房(NICU)采集早产儿的肠道样本 喂人奶，从这些样品中提取多肽成分，测试它们的抗菌、致双歧、 体外IEC调节和巨噬细胞免疫调节活性，并鉴定候选生物活性多肽 通过质谱学、数据库搜索和统计技术进行综合和功能测试。 作为一个子目标，我们将对母体和巴氏杀菌供体母乳进行这一分析。 这项研究具有创新性，因为它首次确定了在体内释放的多肽的生物活性 在活体婴儿消化中，提供了一种识别候选生物活性多肽的方法，并建立了一条管道 用于在相关模型系统中测试候选多肽，包括新生儿肠道。在结束时 在这个项目中，我们希望1)鉴定与肠道健康相关的人乳蛋白衍生肽的生物活性 早产儿肠道提取物和2)鉴定婴儿肠道中存在的特定多肽，这些多肽可以 调节微生物群、IECS和巨噬细胞。这项研究的积极影响是它将提供 利用乳源生物活性多肽改善早产儿和潜在婴儿肠道健康的基础 都是婴儿。

PROJECT SUMMARY Human milk, whether maternal or pasteurized donor human milk, is considered the ideal nutrition for preterm infants. In addition to serving as a source of amino acids to support infant growth, human milk proteins encode cryptic bioactive peptides released during infant digestion. These peptides can be found in the infant intestine luminal fluid and have an array of biological activities, including antimicrobial, bifidogenic, immunomodulatory, and effects on intestinal physiology. Although peptides responsible peptides our initial work demonstrates that milk released and present in the infant intestine have beneficial activities, identifying the specific peptides for these gut-related actions has been limited. Thus, there is a critical need to determine the specific released within the infant's gastrointestinal tract that mediate these bioactivities. Our long-term goal is to leverage the biology of human milk to promote optimal development and growth of preterm infants ex utero. The overall objective of this proposal is to demonstrate the presence and identities of gut health-promoting human milk protein-derived peptides within the preterm infant intestine. Our central hypothesis is that bioactive peptides are released in the infant intestine to modulate gut physiology through the microbiome, intestinal epithelium, and immune system. Our specific aims are to determine the 1) antimicrobial and bifidogenic activity, 2) intestinal epithelial cell (IEC)-specific effects (barrier function, proliferation, differentiation) and 3) macrophage-immunomodulatory activity of peptides in the intestinal contents of preterm infants fed human milk. For each of these activities, we will identify and validate specific peptides. Our approach will be to collect intestinal samples from preterm neonates in the neonatal intensive care unit (NICU) after feeding human milk, extract the peptide component from these samples, test their antibacterial, bifidogenic, IEC-modulatory and macrophage-immunomodulatory activity in vitro, and identify candidate bioactive peptides via mass spectrometry, database searching, and statistical techniques to be synthesized and tested for function. As a sub-aim, we will perform this analysis for maternal and pasteurized donor human milk. This research is innovative because it identifies, for the first time, bioactivities of peptides released during in vivo infant digestion, provides a means for identifying candidate bioactive peptides and establishes a pipeline for testing candidate peptides in relevant model systems, including neonatal human enteroids. At the conclusion of this project, we expect to 1) identify the gut health-related bioactivity of human milk protein-derived peptide extracts from the preterm infant intestine and 2) identify specific peptides present in the infant intestine that can modulate the microbiome, IECs, and macrophages. The positive impact of this research is that it will provide the basis for leveraging milk-derived, bioactive peptides to improve infant gut health for preterm and potentially all infants.